Milking machine pulsator



United States Patent 3,396,750 MILKING MACHINE PULSATOR Rutger Einar Viktor Nilsson, Sodertalje, Sweden, assignor to Alta-Laval AB, Tumba, Sweden, a corporation of Sweden Filed Apr. 1, 1966, Ser. No. 539,545 Claims priority, application Sweden, Apr. 5, 1965, 4,373/65 2 Claims. (Cl. 137--625.25)

This invention relates to milking machine pulsators with a reciprocating slide for providing the connection between the pulsation channels, an evacuation channel and the atmosphere. It is known to arrange the openings of said channels in the slide plane of the pulsator in such a way that the openings for the pulsation channels are located on both sides of the opening of the evacuation channel.

In order to ensure cooperation with these channel openings, the slide is provided with a vacuum chamber which is open towards the slide plane and extends in the direction of motion of the slide, such that during a part of the stroke of the slide, the two pulsation channels are in connection with the evacuation channel. At the beginning of each stroke of the slide one of the pulsation channels is always in connection with the atmosphere and has therefore, when it is shut off from the atmosphere in the course of the slide stroke, a higher pressure than that prevailing in the vacuum chamber of the slide and in the other pulsation channel. Owing to the hitherto customary design of the vacuum chamber with a uniform cross-section along the whole length of the chamber, the higher pressure will cause in the other pulsation channel a temporary pressure increase, which generally is of such a magnitude that a motion of the teat cup liners occur. This motion is detrimental to the milking effect.

The invention has for its object to eliminate this drawback.

This invention is characterized in that the vacuum chamber of the slide is provided with a partition wall extending from the top of the chamber to the proximity' of the slide plane. This wall separates the chamber into two compartments communicating with each other via a narrow channel, which compartments are thus substantially shut off from each other by means of the partition wall.

A further characteristic is that the walls in both compartments are arch-shaped in order to guide the air flowing into the compartments to the evacuation channel.

In the attached drawing,

FIG. 1a shows the prior art embodiment of the pulsation slide seen in vertical section.

FIG. 1b shows a pressure characteristic diagram for such a slide.

FIGS. 2a, 2b, and 20 show vertical sections through a pulsation slide according to the invention in three different positions. FIG. 2d shows a pressure diagram for a pulsator according to this embodiment.

In FIG. 1, a pulsation slide is provided with a vacuum chamber 2 Which is rectangular in longitudinal section and open to the flat surface ,3 of the stationary frame 4 of the pulsator. The pulsation slide 1 moves to and fro by means well known. In the example shown, the reciprocal motion of the slide is indicated by the arrow a. There are three channels which open into the plane 3. They include central evacuation channel 5, as well as two pulsation channels 6 and 7. The latter are located on opposite sides of the evacuation channel 5.

3,396,750 Patented Aug. 13, 1968 In the position shown, the pulsation channel 7, which contains air at atmospheric pressure, has just been put into communication with the slide vacuum chamber 2. Evacuation channel 5 and the pulsation channel 6 are also in full communication with the pulsation channel 7. These communications are indicated in the drawing by means of the flow lines b and c which are provided with arrows. As a consequence of the temporary communication of pulsation channel 6 with pulsation channel 7, pressure increase occurs in the pulsation channel 6, as is indicated at d in the pulsation diagrams in FIG. 1b.

The pulsation slide according to the invention, shown in FIGS. 2a, 2b, and 2c, is like the slide shown in FIG. 1a, designated by 1 and is likewise supposed to move in the direction of the arrow a (FIG. 2b). Also in this case, the slide moves on a flat surface 3 of the pulsator body 4, in which surface a central evacuation channel 5 and two pulsation channels 6 and 7 open in the same way as the embodiment according to FIG. 1a.

The vacuum chamber according to the present invention, shown in FIG. 2, consists of two compartments 21 and 22 placed after each other in the direction of motion of the slide and separated by a partition wall 10 extending from the top of the chamber downwards where it ends a distance above the surface 3 so as to form a vertically narrow communication 11 between both compartments 21 and 22. The Walls of both compartments are archshaped in order to provide smooth guiding for the air flow from the pulsation channels 6, 7 to the evacuation channel 5, as indicated by the arrows e in FIG. 2a and f in FIG. 2c. The partition wall 10 practically prevents all overflow of air at atmospheric pressure between the pulsation channels 6 and 7, when one of said channels is put into communication with the respective compartment of the vacuum chamber after having been shut off from the communication with the atmosphere.

The operation of the pulsation slide is shown in FIGS. 2a-2c. In FIG. 2a, the slide has just left its left-hand end position, in which the pulsation channel 6 was in full communication with the evacuation channel 5 and the pulsation channel 7 was in communication with the atmosphere. In FIG. 2b, the communication between the channel 7 and the atmosphere has been shut off. In FIG. 20, the channel 7 has come in communication with the evacuation channel 5 via the compartment 22 of the evacuation chamber of the slide. The air in the channel 7 flows only over to the evacuation channel 5 since the partition wall 10 prevents it from entering the compartment 21. Therefore, no pressure increase corresponding to d" in FIG. 1b occurs. The pressure diagram has the shape shown in FIG. 2d. In other words, the milking effect is in this case not detrimentally affected by atmospheric air from the pulsation channel 7.

It will be apparent that many modifications may be made within the spirit and scope of my invention and I do not wish to be limited otherwise than as indicated by the terms of the appended claims.

I claim:

1. A milking machine pulsator including pulsation and evacuation channels, and a reciprocating slide having a vacuum chamber for providing the connection between the pulsation channels of the pulsator, the evacuation channel of the pulsator, and the atmosphere, said channels having openings in the slide plane of the pulsator, the openings of the pulsation channels being located on opposite sides of the opening of the evacuation channel, wherein the vacuum chamber of the slide is divided into 3 4. two compartments by a partition wall extending from References Cited the top of the chamber to the proximitv of the slide plane, UNITED STATES PATENTS which compartments communicate with each other by means of a vertically narrow opening between the lower 113,616 4/1871 Barrett 137-62525 edge of the partition wall and the slide plane. 5 142,292 8/1873 137-62525 2. A milking machine pulsator according to claim 1, 2,086,678 7/1937 Plmt et 137-103 XR wherein the walls of the compartments of the vacuum chamber are arcuate in shape to guide the 'air flowing CARY NELSON Primary Exammer' within the compartments to the evacuation channel. R. J. MILLER, Assistant Examiner. 

1. A MILKING MACHINE PULSATOR INCLUDING PULSATION AND EVACUATION CHANNELS, AND A RECIPROCATING SLIDE HAVING A VACUUM CHAMBER FOR PROVIDING THE CONNECTION BETWEEN THE PULSATION CHANNELS FOR THE PULSATION, THE EVACUATION CHANNEL OF THE PULSATOR, AND THE ATMOSPHERE, SAID CHANNELS HAVING OPENINGS IN THE SLIDE PLANE OF THE PULSATOR, THE OPENINGS OF THE PULSATION CHANNELS BEING LOCATED ON OPPOSITE SIDES OF THE OPENING OF THE EVACUATION CHANNEL, WHEREIN THE VACUUM CHAMBER OF THE SLIDE IS DIVIDED INTO TWO COMPARTMENTS BY A PARTITION WALL EXTENDING FROM THE TOP OF THE CHAMBER TO THE PROXIMITY OF THE SLIDE PLANE, WHICH COMPARTMENTS COMMUNICATE WITH EACH OTHER BY MEANS OF A VERTICALLY NARROW OPENING BETWEEN THE LOWER EDGE OF THE PARTITION WALL AND THE SLIDE PLANE. 